A model for negative bias temperature instability in oxide and high κ pFETs

A model for the negative bias temperature instability (NBTI) is proposed. Unlike previous empirical models, this model is derived from physics principles. The model attributes NBTI to de-passivation of SiO2/Si interface and its two distinguishing features are: application of statistical mechanics to calculate depassivated site density increase as a function of stressing conditions and the assumption that the hydrogen diffusion in oxide is dispersive. The model is verified using published NBTI data for SiO 2/poly, SiON/W and HfO2/W pFETs. A comparison between high κ and conventional oxide is made. ©2007 IEEE.